A Long Term Evolution (LTE) network of the 3rd generation mobile communication consists of an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and an Evolved Packet Core (EPC) network.
The E-UTRAN includes a set of Evolved Node Bs (eNBs). The EPC network has a flat architecture, and includes a Mobility Management Entity (MME), a Serving Gateway (S-GW) and the like. Wherein, the eNB and the MME/S-GW are connected through an S1 interface, and the eNBs can be connected with each other through an X2 interface. The S1 interface and the X2 interface are a logic interface. One MME/S-GW can manage one or more eNBs, and one eNB can also be controlled by a certain or multiple MMEs/S-GWs. One eNB can manage one or more cells.
An LTE Advanced (LTE-A) system is evolved from the LTE system, and has the same network architecture as the LTE system. Some new technologies, such as coordinated multiple points, spectrum aggregation and relay, are adopted in the LTE-A system to enhance the system performance.
With the development of wireless communication technology, a Home NB is introduced. The Home NB is a small-sized and low-power NB, which is deployed in home, office and other indoor places, and is mainly used to provide a higher service rate for users, reduce cost required by using high-rate service and make up the deficiency of coverage of an existing wireless communication network. The Home NB is advantaged in being affordable and convenient, low power, plug and play and the like.
As shown in FIG. 1 and FIG. 2, a Home NB user accesses a Core Network (CN) through a Home (e)Node B Access Network (H(e)NB AN), wherein the H(e)NB AN consists of a Home (e)Node B (H(e)NB) and a Home (e)Node B Gateway (H(e)NB GW). The main functions of the H(e)NB GW are: verifying security of the Home NB, processing register and access control of the Home NB and taking charge of exchanging data of the CN and the Home NB. A Home (e)Node B Management System (H(e)MS) is configured to perform maintenance and management on the Home NB, configure and control the Home NB according to requirement of an operator, and most mainly implement configuration management functions for the H(e)NB, wherein the configuration management functions include verification of location information and parameter configuration for the H(e)NB, and the parameter configuration mainly relates to ON-level parameter configuration, parameter configuration of a Radio Access Network (RAN) side and parameter configuration of Radio Frequency (RF). For the H(e)NB system, the H(e)NB can be directly connected with the MME not through the H(e)NB GW.
With the development of Home NB technology, a concept of a Close Subscriber Group (CSG) is introduced for performing grouping management on subscribers, wherein the premise that a subscriber belongs to a certain CSG is that an International Mobile Subscriber Identification (IMSI) number of a terminal device of the subscriber has signed with the CSG. With the introduction of the concept of the CSG, the Home NB introduces a concept aiming at a CSG access mode. The Home NB has three access modes, which are respectively Open access mode, Close access mode and Hybrid access mode. Wherein, the Home NB with the Open access mode allows the contract subscriber and the non-contract subscriber to access and is same as a normal macro cell; the Home NB with the Close access mode allows only the subscriber signed with the CSG to access; and the Home NB with the Hybrid access mode allows both the contract subscriber and the non-contract subscriber to access, but the contract subscriber is superior to the non-contract subscriber in use of resource, that is to say, in resource shortage situations, the Home NB serves the contract subscriber preferentially, and may switch the non-contract subscriber to other cells or release its signaling connection.
Determination of identity with which a User Equipment (UE) accesses a network can be completed according to an allowed CSG list of the UE. The allowed CSG list is an information list of all the signed CSGs of the UE and is stored in a network side and the UE respectively. If the CSG to which the Home NB accessed by the UE belongs is in the allowed CSG list of the UE, then the UE accesses the network as the CSG contract subscriber; otherwise, the UE accesses the network as the non-CSG contract subscriber. For the UE, information of a Home NB cell that the UE ever resided can be kept, for example, the UE can record an E-UTRAN Cell Global Identifier (ECGI), a Tracking Area Identifier (TAI), a CSG Identity (CSG ID), location information and the like of the cell, wherein these information are called footprint information. When the UE in a connection state approaches the Home NB cell again, the UE reports a Proximity Indication (PI) to the network side to notify the network, and the UE itself has approached a Home NB cell that the UE ever resided geographically.
At present, the telecom industry is gradually entering a meager profit era, so the telecom operators are increasingly paying attention to the link of reducing cost (such as energy saving and the like) while achieving growth by expanding market share and business lines. The number of NBs in wireless communication network is very large and energy consumption of the NBs is very high, so how to reduce energy consumption of the NB is one key energy-saving measure.
For a macro cell of the LTE system, an energy-saving function of the cell is implemented by opening and closing the cell. When the cell prepares to enter an energy-saving state, the eNB determines to close the cell and notifies neighbouring eNBs that this service cell has entered an energy-saving sleeping state. However, opening of the cell is waked up by an adjacent eNB; through a cell activating command, an adjacent cell generally wakes up, based on requirement of load and the like, the cell which is in an energy-saving sleeping state to serve a user network.
One way of waking up the Home NB in an energy-saving sleeping state is a triggering way of waking up the Home NB cell through PI reporting of the UE. When the UE learns, according to footprint information kept by the UE itself, that the UE arrives in an area of a Home NB cell in which the UE ever resided but does not search out signals of the Home NB cell, the UE reports PI information to indicate that there should be a Home NB cell but no signal is received; after receiving the PI information and determining that the Home NB cell has been in a sleeping state for saving energy, a network side can consider to wake up the Home NB cell, so as to prepare to provide service for the UE. However, the PI information is sent to the network side by the UE in a connection state.
For a UE in an idle state, when the UE arrives in an area of a Home NB cell in which the UE ever resided, the network side does not know; if the Home NB cell is in a sleeping state for saving energy, then the Home NB cell cannot provide service for the UE by adopting an existing way of waking up the Home NB cell in an energy-saving state.